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Seasonal factors for auto and truck production were revised in March 2009 for the annual revision to the index of industrial production. These factors are based on production data through February 2009 and were revised back to January 2000. Seasonal factors will next revise in mid June 2009, when manufacturers issue their initial assembly plans for the third quarter.
Monthly figures for motor vehicle assemblies in millions of units at an annual rate are published in Table 3 of the G.17 release. The formula for seasonally adjusted annual rates (SAAR) of auto and truck production (in millions of units) for each month is
SAAR = ((NSA data in units/1,000,000) * 12)/(SF * .01).
The not seasonally adjusted (NSA) data are obtained from Ward’s Communications, and the seasonal factors (SF), which contain adjustments for holiday and length-of-month effects as well as normal seasonal variation, are shown in the table below under "Regular Seasonal Factors."
The table below also shows a set of seasonal factors on a weekday average basis in the columns under "Weekday-basis Seasonal Factors"; the number of production days in a month, or weekdays, is shown separately. Using this information, the formula for seasonally adjusted annual rates of auto and truck production (in millions of units) for each month is
SAAR = ((NSA data in units/1,000,000) * 260)/(weekdays * SFW * .01).
Multiplying by 260, the average number of weekdays in a year, converts the weekday average production to an annual production rate. This formula reduces to
SAAR = (NSA data in units * .026) / (weekdays * SFW).A comma-delimited text file containing these seasonal factors is available for download here.
|
Regular Seasonal Factors | Weekday-basis Seasonal Factors | |||||
---|---|---|---|---|---|---|---|
Autos |
Total Trucks |
Light Trucks |
Autos |
Total Trucks |
Light Trucks |
Weekdays |
|
Jan-1998 | 89.68 | 89.71 | 89.99 | 88.32 | 88.35 | 88.63 | 22 |
Feb-1998 | 99.57 | 101.25 | 101.53 | 107.87 | 109.69 | 109.99 | 20 |
Mar-1998 | 113.55 | 114.34 | 114.62 | 111.83 | 112.61 | 112.88 | 22 |
Apr-1998 | 105.41 | 106.46 | 106.32 | 103.81 | 104.84 | 104.71 | 22 |
May-1998 | 105.15 | 105.39 | 105.56 | 108.48 | 108.73 | 108.92 | 21 |
Jun-1998 | 102.70 | 101.53 | 101.32 | 101.15 | 99.99 | 99.79 | 22 |
Jul-1998 | 74.24 | 67.78 | 66.23 | 69.94 | 63.86 | 62.39 | 23 |
Aug-1998 | 99.62 | 95.41 | 95.11 | 102.78 | 98.44 | 98.13 | 21 |
Sep-1998 | 104.04 | 110.29 | 110.77 | 102.46 | 108.61 | 109.09 | 22 |
Oct-1998 | 112.53 | 113.29 | 113.41 | 110.82 | 111.57 | 111.69 | 22 |
Nov-1998 | 93.96 | 93.48 | 93.77 | 96.94 | 96.44 | 96.75 | 21 |
Dec-1998 | 88.57 | 89.47 | 89.50 | 83.44 | 84.28 | 84.31 | 23 |
Jan-1999 | 89.82 | 89.60 | 89.95 | 92.67 | 92.44 | 92.80 | 21 |
Feb-1999 | 99.37 | 101.16 | 101.44 | 107.65 | 109.59 | 109.90 | 20 |
Mar-1999 | 118.59 | 119.54 | 119.83 | 111.71 | 112.61 | 112.89 | 23 |
Apr-1999 | 105.14 | 106.22 | 106.09 | 103.55 | 104.61 | 104.48 | 22 |
May-1999 | 104.81 | 105.12 | 105.25 | 108.14 | 108.45 | 108.59 | 21 |
Jun-1999 | 112.87 | 108.01 | 107.50 | 111.16 | 106.38 | 105.87 | 22 |
Jul-1999 | 63.77 | 61.58 | 60.30 | 62.80 | 60.64 | 59.38 | 22 |
Aug-1999 | 105.84 | 104.65 | 104.59 | 104.23 | 103.06 | 103.00 | 22 |
Sep-1999 | 105.11 | 107.02 | 107.29 | 103.51 | 105.40 | 105.67 | 22 |
Oct-1999 | 106.87 | 107.73 | 107.87 | 110.26 | 111.15 | 111.29 | 21 |
Nov-1999 | 99.80 | 99.20 | 99.53 | 98.29 | 97.70 | 98.03 | 22 |
Dec-1999 | 87.96 | 89.44 | 89.50 | 82.86 | 84.25 | 84.31 | 23 |
Jan-2000 | 94.47 | 93.95 | 94.16 | 97.47 | 96.94 | 97.15 | 21 |
Feb-2000 | 104.57 | 106.14 | 106.45 | 107.89 | 109.51 | 109.83 | 21 |
Mar-2000 | 118.36 | 119.75 | 120.08 | 111.50 | 112.81 | 113.12 | 23 |
Apr-2000 | 94.42 | 95.05 | 94.97 | 102.29 | 102.97 | 102.89 | 20 |
May-2000 | 109.45 | 110.32 | 110.48 | 103.10 | 103.92 | 104.07 | 23 |
Jun-2000 | 112.27 | 110.76 | 110.49 | 110.57 | 109.08 | 108.81 | 22 |
Jul-2000 | 62.32 | 60.76 | 59.63 | 64.30 | 62.69 | 61.52 | 21 |
Aug-2000 | 111.31 | 109.52 | 109.58 | 104.86 | 103.17 | 103.23 | 23 |
Sep-2000 | 100.80 | 98.58 | 98.61 | 104.00 | 101.71 | 101.74 | 21 |
Oct-2000 | 111.51 | 113.10 | 113.20 | 109.82 | 111.39 | 111.49 | 22 |
Nov-2000 | 99.61 | 99.19 | 99.45 | 98.10 | 97.69 | 97.95 | 22 |
Dec-2000 | 82.13 | 84.11 | 84.20 | 84.73 | 86.78 | 86.88 | 21 |
Jan-2001 | 99.46 | 98.17 | 98.33 | 93.70 | 92.48 | 92.63 | 23 |
Feb-2001 | 99.57 | 100.88 | 101.16 | 107.87 | 109.28 | 109.59 | 20 |
Mar-2001 | 112.85 | 114.55 | 114.89 | 111.14 | 112.81 | 113.15 | 22 |
Apr-2001 | 99.60 | 100.03 | 99.95 | 102.76 | 103.20 | 103.12 | 21 |
May-2001 | 114.21 | 115.67 | 115.82 | 107.59 | 108.97 | 109.11 | 23 |
Jun-2001 | 106.79 | 105.54 | 105.31 | 110.18 | 108.90 | 108.65 | 21 |
Jul-2001 | 62.88 | 60.97 | 59.56 | 61.93 | 60.04 | 58.66 | 22 |
Aug-2001 | 113.03 | 110.85 | 110.99 | 106.48 | 104.42 | 104.56 | 23 |
Sep-2001 | 98.31 | 96.16 | 96.34 | 106.51 | 104.17 | 104.37 | 20 |
Oct-2001 | 116.33 | 118.26 | 118.36 | 109.58 | 111.40 | 111.50 | 23 |
Nov-2001 | 99.53 | 99.36 | 99.62 | 98.02 | 97.85 | 98.11 | 22 |
Dec-2001 | 76.69 | 78.70 | 78.81 | 79.12 | 81.19 | 81.31 | 21 |
Jan-2002 | 99.81 | 97.56 | 97.64 | 94.02 | 91.91 | 91.98 | 23 |
Feb-2002 | 99.53 | 100.70 | 100.97 | 107.83 | 109.09 | 109.39 | 20 |
Mar-2002 | 102.21 | 104.13 | 104.45 | 105.46 | 107.43 | 107.77 | 21 |
Apr-2002 | 109.82 | 110.25 | 110.15 | 108.16 | 108.58 | 108.48 | 22 |
May-2002 | 113.53 | 115.53 | 115.66 | 106.94 | 108.83 | 108.95 | 23 |
Jun-2002 | 101.64 | 100.63 | 100.45 | 110.11 | 109.01 | 108.82 | 20 |
Jul-2002 | 70.81 | 65.80 | 64.41 | 66.70 | 61.99 | 60.67 | 23 |
Aug-2002 | 103.94 | 103.49 | 103.62 | 102.37 | 101.92 | 102.05 | 22 |
Sep-2002 | 101.98 | 100.99 | 101.15 | 105.22 | 104.20 | 104.36 | 21 |
Oct-2002 | 116.31 | 117.86 | 117.94 | 109.56 | 111.03 | 111.10 | 23 |
Nov-2002 | 89.19 | 88.99 | 89.24 | 92.03 | 91.82 | 92.08 | 21 |
Dec-2002 | 76.49 | 78.61 | 78.72 | 75.33 | 77.42 | 77.53 | 22 |
Jan-2003 | 100.06 | 96.87 | 96.86 | 94.26 | 91.26 | 91.25 | 23 |
Feb-2003 | 99.44 | 100.51 | 100.78 | 107.73 | 108.89 | 109.18 | 20 |
Mar-2003 | 107.09 | 109.20 | 109.53 | 110.49 | 112.66 | 113.01 | 21 |
Apr-2003 | 104.08 | 105.01 | 104.91 | 102.50 | 103.41 | 103.32 | 22 |
May-2003 | 107.52 | 110.05 | 110.14 | 105.89 | 108.39 | 108.47 | 22 |
Jun-2003 | 102.98 | 102.51 | 102.41 | 106.25 | 105.76 | 105.66 | 21 |
Jul-2003 | 74.32 | 67.80 | 66.52 | 70.01 | 63.87 | 62.66 | 23 |
Aug-2003 | 103.32 | 101.42 | 101.60 | 106.60 | 104.64 | 104.83 | 21 |
Sep-2003 | 103.76 | 105.00 | 105.08 | 102.18 | 103.41 | 103.48 | 22 |
Oct-2003 | 116.51 | 117.07 | 117.12 | 109.75 | 110.29 | 110.33 | 23 |
Nov-2003 | 90.65 | 90.68 | 90.95 | 98.20 | 98.23 | 98.53 | 20 |
Dec-2003 | 86.46 | 89.30 | 89.42 | 81.44 | 84.13 | 84.23 | 23 |
Jan-2004 | 92.05 | 88.38 | 88.30 | 90.65 | 87.04 | 86.96 | 22 |
Feb-2004 | 99.62 | 100.36 | 100.62 | 107.92 | 108.73 | 109.00 | 20 |
Mar-2004 | 117.35 | 119.57 | 119.93 | 110.54 | 112.64 | 112.98 | 23 |
Apr-2004 | 104.82 | 106.51 | 106.42 | 103.24 | 104.90 | 104.80 | 22 |
May-2004 | 99.67 | 102.72 | 102.78 | 102.84 | 105.98 | 106.04 | 21 |
Jun-2004 | 111.54 | 111.65 | 111.63 | 109.85 | 109.95 | 109.94 | 22 |
Jul-2004 | 69.87 | 64.35 | 63.09 | 68.81 | 63.37 | 62.14 | 22 |
Aug-2004 | 107.28 | 104.55 | 104.65 | 105.65 | 102.97 | 103.07 | 22 |
Sep-2004 | 107.48 | 108.04 | 108.29 | 105.85 | 106.40 | 106.65 | 22 |
Oct-2004 | 106.58 | 106.21 | 106.22 | 109.96 | 109.58 | 109.59 | 21 |
Nov-2004 | 97.46 | 97.65 | 97.98 | 95.99 | 96.17 | 96.50 | 22 |
Dec-2004 | 86.18 | 89.43 | 89.53 | 81.18 | 84.25 | 84.34 | 23 |
Jan-2005 | 96.93 | 92.35 | 92.19 | 100.01 | 95.29 | 95.12 | 21 |
Feb-2005 | 100.02 | 100.25 | 100.49 | 108.35 | 108.61 | 108.86 | 20 |
Mar-2005 | 108.82 | 110.71 | 111.03 | 102.51 | 104.29 | 104.59 | 23 |
Apr-2005 | 107.50 | 110.12 | 110.01 | 110.92 | 113.61 | 113.50 | 21 |
May-2005 | 103.54 | 107.58 | 107.61 | 101.97 | 105.95 | 105.98 | 22 |
Jun-2005 | 111.21 | 112.35 | 112.45 | 109.52 | 110.65 | 110.75 | 22 |
Jul-2005 | 65.54 | 60.81 | 59.60 | 67.62 | 62.75 | 61.49 | 21 |
Aug-2005 | 115.20 | 111.51 | 111.79 | 108.52 | 105.04 | 105.31 | 23 |
Sep-2005 | 106.98 | 106.50 | 106.68 | 105.36 | 104.89 | 105.07 | 22 |
Oct-2005 | 107.11 | 105.87 | 105.84 | 110.51 | 109.23 | 109.20 | 21 |
Nov-2005 | 93.61 | 94.05 | 94.39 | 92.19 | 92.62 | 92.96 | 22 |
Dec-2005 | 85.75 | 89.39 | 89.47 | 84.45 | 88.04 | 88.12 | 22 |
Jan-2006 | 96.97 | 91.70 | 91.47 | 95.50 | 90.31 | 90.08 | 22 |
Feb-2006 | 100.24 | 100.28 | 100.50 | 108.59 | 108.63 | 108.88 | 20 |
Mar-2006 | 117.62 | 119.49 | 119.84 | 110.80 | 112.57 | 112.89 | 23 |
Apr-2006 | 93.14 | 95.90 | 95.78 | 100.90 | 103.89 | 103.76 | 20 |
May-2006 | 109.20 | 114.32 | 114.34 | 102.87 | 107.70 | 107.71 | 23 |
Jun-2006 | 110.93 | 112.97 | 113.18 | 109.25 | 111.26 | 111.46 | 22 |
Jul-2006 | 67.30 | 60.79 | 59.61 | 69.43 | 62.72 | 61.50 | 21 |
Aug-2006 | 114.90 | 112.74 | 113.14 | 108.23 | 106.21 | 106.58 | 23 |
Sep-2006 | 102.12 | 101.15 | 101.25 | 105.36 | 104.36 | 104.47 | 21 |
Oct-2006 | 112.79 | 110.78 | 110.73 | 111.08 | 109.10 | 109.05 | 22 |
Nov-2006 | 97.00 | 97.63 | 97.99 | 95.53 | 96.15 | 96.50 | 22 |
Dec-2006 | 80.47 | 84.11 | 84.18 | 83.02 | 86.78 | 86.85 | 21 |
Jan-2007 | 101.77 | 95.59 | 95.26 | 95.87 | 90.05 | 89.74 | 23 |
Feb-2007 | 100.39 | 100.35 | 100.57 | 108.76 | 108.71 | 108.95 | 20 |
Mar-2007 | 112.58 | 114.25 | 114.58 | 110.87 | 112.52 | 112.85 | 22 |
Apr-2007 | 97.78 | 101.09 | 100.94 | 100.89 | 104.30 | 104.15 | 21 |
May-2007 | 108.35 | 114.30 | 114.30 | 102.07 | 107.67 | 107.67 | 23 |
Jun-2007 | 105.57 | 108.41 | 108.71 | 108.93 | 111.85 | 112.16 | 21 |
Jul-2007 | 73.71 | 66.20 | 65.07 | 72.59 | 65.20 | 64.09 | 22 |
Aug-2007 | 113.19 | 111.25 | 111.59 | 106.63 | 104.80 | 105.12 | 23 |
Sep-2007 | 97.49 | 95.75 | 95.83 | 105.62 | 103.73 | 103.82 | 20 |
Oct-2007 | 118.55 | 115.88 | 115.82 | 111.68 | 109.16 | 109.11 | 23 |
Nov-2007 | 100.58 | 101.64 | 102.00 | 99.05 | 100.10 | 100.45 | 22 |
Dec-2007 | 75.28 | 78.90 | 78.95 | 77.67 | 81.41 | 81.45 | 21 |
Jan-2008 | 102.18 | 95.19 | 94.79 | 96.25 | 89.67 | 89.29 | 23 |
Feb-2008 | 105.34 | 105.28 | 105.51 | 108.69 | 108.63 | 108.86 | 21 |
Mar-2008 | 99.29 | 100.58 | 100.88 | 102.44 | 103.77 | 104.08 | 21 |
Apr-2008 | 110.88 | 115.26 | 115.07 | 109.20 | 113.51 | 113.33 | 22 |
May-2008 | 101.39 | 107.70 | 107.68 | 99.85 | 106.07 | 106.05 | 22 |
Jun-2008 | 105.50 | 108.99 | 109.38 | 108.84 | 112.45 | 112.85 | 21 |
Jul-2008 | 75.16 | 69.45 | 68.30 | 70.80 | 65.43 | 64.34 | 23 |
Aug-2008 | 105.16 | 100.26 | 100.54 | 108.49 | 103.44 | 103.73 | 21 |
Sep-2008 | 108.28 | 106.39 | 106.53 | 106.64 | 104.78 | 104.91 | 22 |
Oct-2008 | 119.15 | 115.69 | 115.61 | 112.24 | 108.98 | 108.91 | 23 |
Nov-2008 | 86.69 | 87.96 | 88.28 | 93.91 | 95.29 | 95.64 | 20 |
Dec-2008 | 85.22 | 89.59 | 89.62 | 80.28 | 84.40 | 84.43 | 23 |
Jan-2009 | 92.67 | 85.79 | 85.38 | 91.26 | 84.49 | 84.09 | 22 |
Feb-2009 | 100.11 | 99.95 | 100.15 | 108.45 | 108.28 | 108.49 | 20 |
Mar-2009 | 112.95 | 114.24 | 114.56 | 111.24 | 112.51 | 112.82 | 22 |
Apr-2009 | 103.27 | 107.98 | 107.79 | 101.70 | 106.34 | 106.16 | 22 |
May-2009 | 96.01 | 102.55 | 102.53 | 99.06 | 105.80 | 105.78 | 21 |
Jun-2009 | 110.46 | 114.68 | 115.18 | 108.79 | 112.94 | 113.43 | 22 |
Jul-2009 | 74.17 | 68.77 | 67.60 | 69.87 | 64.78 | 63.68 | 23 |
Aug-2009 | 106.34 | 101.68 | 102.01 | 109.72 | 104.91 | 105.25 | 21 |
Sep-2009 | 108.75 | 105.48 | 105.60 | 107.10 | 103.89 | 104.00 | 22 |
Release dates |
Historical data |
Documentation
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PDF (144 KB)
Supplemental Monthly Release
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PDF (144 KB)
Annual Revision Release
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PDF (150 KB)